1. Field of the Invention
The present invention is broadly concerned with a slitting mechanism designed for use in a bottomer apparatus especially adapted for creating double fold bag closures of the type described in pending application for U.S. patent Ser. No. 462,026 filed Jan. 28, 1983. More particularly, it is concerned with such a slitter mechanism which provides uniform, high speed, automated marginal end slitting required for subsequent downstream gluing and folding operations in the bottomer apparatus.
2. Description of the Prior Art
A recent, significant advance in the art of container bags is represented by the so-called "double fold" end closure. Such double fold bags, and their methods of manufacture, are disclosed in application for U.S. patent Ser. No. 462,026 filed Jan. 28, 1983, and such application is expressly incorporated by reference herein.
As disclosed in the referenced patent application, the first step in forming a double fold closure end involves providing a pair of short cut lines or slits in the open end of a bag-forming tube, typically at the juncture between a front or rear panel and the side closure panels. Such cut lines can be made either between the front and rear panels proper, or between the plys of one of the panels if the bag-forming tube is of a multiple-ply variety.
Obviously, if double fold closure ends are to become commercially important, the forming of such ends must be accomplished on a high speed, automated basis. While the necessary gluing and folding operations do not present any significant problems in this regard, a real difficulty is presented in connection with providing the necessary side marginal cut lines or slits in the bag-forming tubes. As will be appreciated, any commercially viable slitter mechanism must not only be able to handle many tubes per minute (on the order of 100 or more), but in addition the resulting slits must be of uniform depth and position if the resultant bags and the double fold closures are to be of commercial quality.